JP2547772Y2 - Hydraulic circuit control device for construction machinery - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention relates to a hydraulic actuator corresponding to a plurality of components such as an arm, a boom, a bucket, a turning section, a traveling section and the like. Prepared,
The present invention relates to a hydraulic circuit control device for a construction machine in which the operation of these hydraulic actuators is switched and controlled by pilot pressure.

[Conventional technology]

FIG. 2 is a hydraulic circuit diagram of a conventional hydraulic circuit control device for a construction machine, and FIG. 2 shows a hydraulic circuit of a hydraulic shovel.

In FIG. 2, reference numerals 1A, 1B, 1C, 1D, and 1E denote hydraulic cylinders as hydraulic actuators for extending and retracting working parts such as a boom, a bucket, and an arm, respectively, and 1F denotes a turning actuator as a hydraulic actuator for turning the working parts. The hydraulic motor, 1G, is a traveling hydraulic motor that governs the traveling of the aircraft.

2A, 2B, 2C, 2D, 2E, 2F, and 2G are control valves provided for the hydraulic cylinders 1A to 1E and the hydraulic motors 1F and 1G, respectively.The hydraulic valves 1A to 1E and the hydraulic It controls the operation / stop of the motors 1F and 1G and the switching of the operation direction. Reference numeral 3 denotes a main pump which is driven by a motor 4 and supplies oil in an oil tank 5 to the hydraulic cylinders 1A to 1E and the hydraulic motors 1F and 1G via the control valves 2A to 2G.

6A, 6B, 6C, and 6D are pilot pressure generating valves, each of which has two pressure reducing valves 6a1, 6a2, 6b1, 6b2, 6c1, whose set pressure is set by operating levers 7A, 7B, 7C, and 7D, respectively.
6c2, 6d1 and 6d2 are built in, and the oil in the oil tank 5 is supplied through a pilot pump 8 to generate a pilot pressure.

9a1, 9a2, 9b1, 9b2, 9c1, 9c2, 9d1, 9d2 are the above-mentioned pressure reducing valves 6a
1,6a2 to 6d1,6d2 pilot pressure generating ports and pilot pressure receiving sections 2a1,2a2,2b1, of the above control valves 2A to 2G
2b2, 2c1, 2c2, 2d1, and 2d2 are respectively connected to the pilot pressure oil passages, and the pilot pressures generated by the pilot pressure generating valves 6A to 6D in response to the operation of the operation levers 7A to 7D are used as the control valves. The control valves 2A to 2G are transmitted to control the switching of the control valves 2A to 2G.

Reference numeral 10 denotes a multi-mode switching valve, which is arranged in the middle of the pilot pressure oil passages 9a1, 9a2 to 9d1, 9d2, and is slid in a detent manner to switch to a plurality of positions a, b, c, d. Each of the above hydraulic cylinders 1A to 1E and hydraulic motors 1F, 1
Convert the operation pattern of G to multiple modes.

11a1, 11a2, 11a3 are communication paths 12a1, 12 connected to oil paths 9a1, 9a2, 9b1, 9b2 in the pilot pressure generating valves 6A, 6B.
a2 and 12a3, each of which is a shuttle valve.
When any one of 1,6a2,6b1,6b2 is operated, it prevents the pilot pressure from escaping through the other pressure reducing valve, and detects the pilot pressure at the output port of the shuttle valve 11a1. The pressure detector 13A is connected.

11b1, 11b2, 11b3 are communication paths 12b1, 12 connected to oil paths 9c1, 9c2, 9d1, 9d2 in the pilot pressure generating valves 6C, 6D.
Shuttle valves provided for b2 and 12b3, respectively,
When any one of 1,6c2,6d1,6d2 is operated, it prevents the pilot pressure from escaping through the other pressure reducing valve, and detects the pilot pressure at the outlet port of the shuttle valve 11b3. The pressure detector 13B is connected.

The above-mentioned shuttle valves 11a1 to 11a3 and 11b1 to 11b3 are integrally built in the valve bodies of the pilot pressure generating valves 6A, 6B and 6C, 6D.

 Next, the operation of the above configuration will be described.

For example, when the operating lever 7A is operated to operate the pressure reducing valve 6a1 or 6a2 of the pilot pressure generating valve 6A, the pilot pressure (oil pressure) supplied from the pilot pump 8 is generated in the oil passage 9a1 or 9a2. This oil passage 9a1 or 9
The pilot pressure generated at a2 is sent to the pilot pressure receiving portion 2a1 or 2a2 of the control valve 2A via the multi-mode switching valve 10, and controls the control valve 2A to switch in a predetermined direction. In accordance with the switching control of the control valve 2A, the oil in the oil tank 5 is pressure-fed by the main pump 3 to the hydraulic cylinder 1A via the control valve 2A, and a working part such as a boom is extended or contracted.

In this case, a pilot pressure is generated in the communication passage 12a1 or 12a2 via the shuttle valve 11a1, while the shuttle valve 11
a2,11a3 or 11a, 11a3 are non-operating pressure reducing valves 6a2,6b1,6b2
Alternatively, the pilot pressure is prevented from escaping from 6a1, 6b1, 6b2. At the same time, the pilot pressure signal of the oil passage 9a1 is detected by the pressure detector 13A, and the operating state of the hydraulic cylinder 1A can be detected.

Although the above description has been made on an example in which the operating lever 7A operates the pressure reducing valve 6a1 or 6a2 of the pilot pressure generating valve 6A to extend or contract the hydraulic cylinder 1A, the pilot pressure is controlled by the operating lever 7A. Pilot pressure generating valve by operating valve 6B and operating lever 7B
In the case of operating 6C or 6D, the operation is performed in the same manner as described above, except that the operation target is changed to the hydraulic cylinders 1B to 1E and the hydraulic motors 1F and 1G.

The multi-mode switching valve 10 is slid in a detent manner to switch between a plurality of positions a to d, so that the oil passages 9a1, 9a2 to 9d on the side of the pilot pressure generating valves 6A to 6D.
It is possible to convert the communication state between 1, 9d2 and the oil passages on the control valves 1A to 1E into a plurality of types and convert the operation pattern of the hydraulic shovel into a plurality of modes.

[Problems to be solved by the invention]

By the way, in the conventional hydraulic circuit control device for construction machinery described above, since the shuttle valve is disposed between the pilot pressure generating valve and the multi-mode switching valve, the operation pattern of the plurality of hydraulic actuators is controlled by the multi-mode switching valve. In this case, since the correspondence between the shuttle valve and the control valve is different, it is not possible to specify which hydraulic actuator the pilot pressure detection signal taken out of the shuttle valve is an operation signal from, and the pressure detection is not possible. Of the pressure detection signal is weakened, and the pressure detection signal is likely to be erroneously recognized.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a hydraulic circuit control device for a construction machine which can always detect an operation signal of a predetermined hydraulic actuator regardless of a change in an operation pattern. .

[Means for solving the problem]

In order to achieve the above object, a hydraulic circuit control device for a construction machine according to the present invention includes a plurality of hydraulic actuators, a control valve for switching and controlling the operation and operating direction of each of the hydraulic actuators, and an operation of an operation lever. A pilot pressure generating valve for generating a pilot pressure for performing the switching control of each of the control valves in response thereto; and a pilot pressure generating valve disposed in the middle of an oil passage connecting each of the pilot pressure generating valves and each of the control valves. A multi-mode switching valve capable of converting the operation pattern of the hydraulic actuator into a plurality of modes; a shuttle valve for extracting a pilot pressure from at least one of the oil passages; and a pressure for detecting a pilot pressure extracted from the shuttle valve. A hydraulic circuit control device for a construction machine, comprising: The in which it arranged between the multi-mode switching valve and control valve.

[Action]

According to this invention, since the shuttle valve is disposed between the multi-mode switching valve and the control valve, no matter how the operation pattern of the plurality of hydraulic actuators is changed by the multi-mode switching valve, the shuttle valve can be used. The correspondence between the control valve and the control valve is kept constant. As a result, the pressure detector that detects the pilot pressure taken out of the shuttle valve specifies which hydraulic actuator the detected pressure signal is an operation signal of, and it is always appropriate to grasp the operation status by visually checking the detected pressure signal. Can be assured.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a hydraulic circuit of a hydraulic shovel as an example of a construction machine. In FIG. 1, the same or corresponding parts as those in the conventional example shown in FIG. I do.

In FIG. 1, the point different from the conventional example of FIG. 2 is that the shuttle valves 11a1, 11a2, 11a3 and 11b1, 11b2, 11b3 are arranged between the multi-mode switching valve 10 and the plurality of control valves 2A to 2G. In addition, these shuttle valves 11a1 to 11b3 are integrated into the valve body of the multi-mode switching valve 10, and accordingly, the pressure detectors 13A and 13B are located downstream of the multi-mode switching valve 10. Are connected to the oil passages 9a1 and 9b2.

In the hydraulic circuit of the hydraulic shovel having the above configuration, the second
The operation is the same as described in the conventional example shown in FIG. Here, the correspondence between the shuttle valves 11a to 11b3 and the control valves 1A to 1E is always constant even when the operation pattern of the hydraulic shovel is changed to any of multiple modes by sliding the multi-mode switching valve 10 in a detent manner. Is kept. Accordingly, the pressure detection signals from the pressure detectors 13A and 13B become operation signals for the set hydraulic actuator, that is, the oil passage 9a1 connected to the hydraulic cylinder 1A and the hydraulic motor 1G.

In the above embodiment, the multi-mode switching valve 10
Although a slide valve of a detent type is used as the above, a rotary valve may be used.

Although the above embodiment has been described as applied to a hydraulic shovel, it may also be applied to a mobile crane, a bulldozer, and the like.

[Effect of the invention]

As described above, according to the present invention, it is possible to always detect the set operation signal of the hydraulic actuator even when the operation pattern of the construction machine is changed to any of the multiple modes simply by changing the arrangement of the shuttle valve. Can be. Therefore, it is possible to always accurately grasp the operation status by visually recognizing the operation signal of the hydraulic actuator.

[Brief description of the drawings]

FIG. 1 is a hydraulic circuit diagram of a hydraulic shovel according to an embodiment of the present invention, and FIG. 2 is a hydraulic circuit diagram of a conventional hydraulic shovel. 1A ~ 1E …… Hydraulic cylinder (hydraulic actuator), 1F, 1
G …… Hydraulic motor (hydraulic actuator), 2A ~ 2G ……
Control valve, 6A to 6D …… Pilot pressure generating valve, 9a
1,9a2 ~ 9d1,9d2 ... oil passage, 10 ... multi-mode switching valve,
11a1,11a2,11a3,11b1,11b2,11b3 …… Shuttle valve, 13A, 1
3B …… Pressure detector.

Continuation of the front page (56) References JP-A-2-171428 (JP, A) JP-A-60-250131 (JP, A) JP-A-62-297513 (JP, A)

Claims (1)

(57) [Scope of request for utility model registration] A plurality of hydraulic actuators, a control valve for controlling the operation and the direction of operation of each of the hydraulic actuators, and a pilot pressure for controlling the switching of each of the control valves in accordance with the operation of an operating lever. And a multi-mode switching valve arranged in the middle of an oil passage connecting these pilot pressure generating valves and the control valves to convert the operation pattern of the hydraulic actuators into a plurality of modes. A hydraulic pressure control device for a construction machine, comprising: a shuttle valve for extracting pilot pressure from at least one of the oil passages; and a pressure detector for detecting the pilot pressure extracted from the shuttle valve. The shuttle valve is located between the multi-mode switching valve and the control valve Hydraulic circuit control system for a construction machine characterized by and.